Beasts, Lovers, and the Clueless
by AdenHolmes
Summary: Sherlock has a crush and Mycroft decides to give Sherlock a little present for Christmas he has wanted for a number of years. In which Sherlock gets sentimental and Mycroft just wants a good lay.Eventual mild pain kink. Holmescest! One-Shot for now! R&R


**Summary: Sherlock has a crush and Mycroft decides to give Sherlock a little present for Christmas he has wanted –needed- for a number of years. In which Sherlock gets sentimental and Mycroft just wants a good lay. Jealousy ensues. Eventual mild pain kink. Holmescest! DP**

**Please R&R I want to know what about this was good and what was bad bc I don't write a lot of sex scenes.**

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><p>Sherlock Holmes always thought he was careful about who saw his feelings, if he allowed anyone to see them at all, but it would seem the one thing he really wanted to keep quiet was the one thing Mycroft noticed. The younger of the Holmes boys had a <em>crush<em>, but of course it couldn't be that simple –this is Sherlock we're talking about. No, not only did Sherlock have a crush he had a crush on his younger _sister._ Surly you'd expect Mycroft, being the eldest, to be disgusted with the concept of his brother and sister being _together_, but well there wouldn't be a story if that were the case.

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><p>Katherine Holmes was never very interested in the activities with which her two elder brothers seemed to immerse themselves –in their detective work. Despite the genes of the Holmes family Katherine was neither psychotic nor a sociopath though she was quite bright. In fact she had landed herself a position in software design for Microsoft in the United States –on a work permit of course-, but it was Christmas and she had taken a flight home to stay with her brother's for the holiday season –never missing work meant she had accumulated enough vacation days for almost the whole month of December. Rather than staying in the cramped flat of 221B with Sherlock and his flat mate John Watson Katherine had opted to stay with Mycroft at his decent sized town home in Mayfair.<p>

It was mid-day December 12th when Katherine's plane landed and she found that, of course, Mycroft had not come to fetch her from the airport and had instead sent a car for her instead. The ride to her eldest brother's home was quiet and solitary which was nice after the bustle of New York –not to say London wasn't busy, but she was happily cut off from the world in the back of the jet black Mercedes. When the car stopped signaling she had arrived at her destination the door was opened for her, luggage was taken into the house, and she was allowed a moment to take in the street a small smile playing at her lips. Mycroft had always been one for self-indulgence. Upon entering the house Katherine was informed that Mycroft would be working until seven, that Sherlock was due to come around eight thirty, and was then escorted to her room. Katherine thanked the maid and closed the door in hopes she could take a nice nap before her brother arrived in the next few hours.

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><p>Despite his promise to arrive him around seven Mycroft decided to take a detour on the way home from work and instead stopped at 221B to pick up Sherlock and have a nice little chat in the car. He after all had been planning the whole ordeal for quite some time –and was sure his brother knew he was up to something- and it was time to let Sherlock in the loop. Mycroft waited patiently in the back of the car after having sent Sherlock a text explaining that he was waiting outside. Of course he received a nasty reply about how he was capable of getting himself places, but none the less came out the front door a few minutes later and pulled open the door to the car.<p>

"Afternoon brother," Mycroft said, a dangerous smirk curling his lips.

Sherlock said nothing and instead opted to fix Mycroft with an accusatory stare.

"I assumed you'd like to know why I've stopped to pick you up."

Again Sherlock declined the prompt to speak.

"You know that Katherine is visiting for the Holidays," Mycroft said.

"Yes, of course I do," Sherlock scoffed, finally releasing himself from his mental vow of silence. "Your point?"

Sherlock was never comfortable in an enclosed space with Mycroft because he knew Mycroft knew his _dirty_ little secret about his feelings for their younger sister.

"Haven't you figured it out?" Mycroft teased.

Sherlock said nothing.

"It must _hurt soo_ much to have to say that you don't know," Mycroft taunted.

"I don't know," Sherlock retorted sarcastically.

Mycroft chuckled. "Yes, well I didn't really expect you to be very cooperative or accepting of my help."

Sherlock snorted. "Help with what?"

"Katherine."

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><p>Katherine's deep brown eyes fluttered open at the soft sound of someone tapping on her chamber door. Though she was groggy and still quite jetlagged she pushed the duvet off her body allowing the chilled air of the room to hit her skin causing goose flesh to pop up on its surface. She grumbled to herself under her breath as she turned the door handle to face the intruder.<p>

"Miss Holmes, your brothers request your presence in the elder Mister Holmes' study," said the maid sweetly.

"Thank you." Katherine nodded before shutting the door.

She felt strangely giddy as she strode across the room over to her case to find a pair of jeans and a t-shirt, but she attributed it to the fact she hadn't seen either of her brothers in a year and she must simply be excited. After changing and slipping on a pair of fuzzy socks to protect her bare feet from the chilled hardwood Katherine exited her room in search of Mycroft's study.

It took her less than five minutes to find her way to his study though she found both doors were closed, so she felt compelled to knock before entering.

"Boys?" she called in a cheery tone as she pushed the door open.

To her pleasant surprise Mycroft's study was heated by a roaring fire on the side of the room opposite the door, and everything was furnished with a dark shade of wood. The whole room left you with a homey impression of the place which she found rather comical; well she did until her eyes fell on the scene before her.

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><p>"I don't know about this," Sherlock said a nervous look colouring his visage.<p>

Mycroft chuckled as he removed his blazer.

"Are you sure?" he asked.

"Little brother," Mycroft began resting a hand on Sherlock's shoulder and squeezing it lightly as he leaned in to whisper in his ear. "I assure you, I am. Women are aroused by men engaging in homosexual acts in the same way men are with women."

Sherlock bit his lip trying to ignore she shiver that ran down his spine. Mycroft had made him an offer he could not bring himself to refuse, even though he had wanted to, that according to him would result in some very un-brother -and-sister like activities –the kind of activities Sherlock had fantasized about Katherine since she was seventeen and him twenty two.

He was left little time to react before Mycroft leaned down to his neck and began kissing it hungrily sucking at the pale flesh and drawing blood to the surface. Sherlock was sure that would leave a mark though he was unable to voice any protest and instead found a husky groan rolling off his lips to linger in the sexually charged air. His brother's smooth fingers traced his jaw bone before tilting his head more to the side allowing for easier access to the pallid skin of Sherlock's neck. Again what Sherlock would later claim as an involuntary groan escaped his lips and a flush spread across his cheeks as he felt himself stirring in his pants.

Her first instinct had been to yell at them both followed by a string of expletives that would make a sailor blush, but before she could even open her mouth she was cut off.

"Hello Kat," Mycroft said.

It was clear to see that not only was his face clouded with arousal and lust, but it had taken hold of even the sound of his voice turning it lazy almost as though it were only a slur of syllables and not actual words. Though she couldn't dwell for long on the words or their intent for long before her eyes were drawn again to the captivating scene before her. It was a scene she certainly ought to be horrified by.

Before her in the arm chair by the fire was her eldest brother Mycroft sitting comfortably with his head lulled back, fully dressed, and his cheeks flushed. This was of course not the part of the scene which surprised her the most. In fact it surprised her the least -Mycroft was certainly the sort to assert dominance in such a fashion- no what got to her was Sherlock. The younger Holmes brother was stripped down to nothing but a pair of black silk boxers which contrasted extremely to his pale skin and hung loosely on his thin frame. He was on his knees before Mycroft with his hand wrapped around a surprisingly large cock that -she hadn't even known he possessed- was protruding from the crisp pair of dress pants.

"I-" she began to stutter which clearly amused Mycroft because his grin doubled in size as a response.

"I should- I should probably go," she muttered taking a step back.

Her eyes were wide and staring though she could not drag them away from Sherlock as he leaned forward and pressed his tongue to the head of Mycroft's cock which solicited a throaty moan from the latter. At her words though Sherlock, for the first time, looked up at her with a pout on his lips that made him look years younger.

"Stay," he begged.

Katherine's jaw fell open as it dawned on her. They would not have summoned her if they hadn't wanted her to see them like this. If they had wanted it kept a secret she'd have never known, but not they had sent a maid to summon her from her room so that she could witness this.

"You've planned this," she said in a cool voice once she had gained some composure.

Mycroft smirked; his fingers knitted into Sherlock's curls, and pushed his mouth down on him causing both men to groan.

"Very good deduction," Mycroft cooed.

He was mocking her. Katherine frowned and pushed the door closed behind her before she swept across the room to take the seat across from him.

"I suppose I shouldn't bother to ask _why_ you wished me to see this display," she said, eyes still fixated on Sherlock.

"I'm sure you've already worked it out," Mycroft said through labored breaths.

There was a pause during which both of their eyes fell on Sherlock as he bobbed his head speedily up and down Mycroft's length.

"He's quite talented with his mouth," Mycroft said slowly urging Sherlock to release him which he did. "Wouldn't you like to see?"

Katherine exhaled the breath she didn't realize she had been holding and shook her head. She could feel the heat in her cheeks as they burned with embarrassment.

"Pity," Mycroft said.

Both brothers got to their feet and Katherine arched an eyebrow wondering what exactly they were playing at. Mycroft put his hand to Sherlock's shoulder and pushed him down until his chest was flat against the desk. As he began to slowly remove Sherlock's boxers he seemed to be whispering something to his younger brother, but it was too quiet for Katherine to hear from her where she sat. Mycroft then reached into his desk and pulled out a bottle of lube.

An Katherine had to bit her lip and look away as her elder brother slicked up his first and middle fingers before pressing them into Sherlock's hole. Though she wouldn't readily admit it a shiver through her body as she heard Sherlock whimper in slight discomfort at the intrusion. For a moment Katherine listened in silence as Mycroft worked his fingers in and out of Sherlock –she could hear the discomfort in his whines lessening with every thrust inward- she debated whether or not she should just get up and leave. The whole situation was wrong on a number of levels and the fact that she could feel herself becoming aroused just listening to her brother being pleasure by her _other_ brother alarmed her. She bit the inside of her cheek and got to her feet just as she hear Sherlock groan –Mycroft must have removed his fingers she thought.

"Won't you join us sister?" Mycroft cooed.

Her back was too them but she could feel both pairs of eyes on her, the same eyes that she had known since she was a little girl. It disturbed her slightly that when she turned to face them again and saw Mycroft pouring a generous amount of lube onto his hand to slick up his cock that she did not shudder in disgust.

"What are you playing at?" she asked her eyes narrowed slightly.

Mycroft smiled. It was a smile she knew and it always meant the entire thing had been planned. _But of course it had to have been!_ He gestured her to come over to them and she did after a moment's hesitation.

"What are you playing at?" she inquired again looking straight up into his eyes.

"Sherlock has simply been so _very lonely_ since his favourite sister has been away," Mycroft cooed again.

She reached out and slapped him right across the face.

"What would mummy say about all this? Don't you think she's turning over in her grave!" Katherine said in a reprimanding tone.

Both brother's chuckled.

"I fail to see the comedy in this," she said crossing her arms over her chest.

"The comedy," Sherlock began moving to stand straight and face her. "Is really you."

She scowled and made as much effort as she could to look anywhere, but below their waists.

"You're trying so hard to not show how much this is getting to you," Sherlock said gesturing between himself and Mycroft. "But really that's what's given it away."

Katherine huffed and made to walk away but a hand wrapped firmly around her wrist and jerked her back. She looked up at Sherlock in surprise to see his long fingers wrapped around her wrist and pressing her hand to his chest.

"You know I love you?" he asked in a soft earnest voice.

She gave him a puzzled look and nodded. "You're my brother."

Sherlock smiled at her and released her hand to instead grasp the collar of her shirt and pull her closer to him until his chest was flush against hers. He pressed his lips to her forehead and started to slowly undo the buttons on her blouse one at a time, being sure to give her time to resist should she choose to, but she didn't. Katherine stood in slightly stunned silence her eyes moving between Sherlock and Mycroft. It felt like her head was spinning as he pushed the blouse off her shoulders and to the floor. Then Mycroft was behind her his fingers quickly undoing the clasp of her bra and discarding the garment as well. Chilled air of the room licked her pale skin bringing blood to the surface in a flush of slight embarrassment as she felt her nipples hardening, from not only the cold, but arousal. Warm hands cupped her breasts as equally warmed lips were pressed to her neck as well as somewhere near her naval. Katherine released a soft whimper. She was only partially aware of the fact Sherlock was removing her trousers as well as her knickers because of the attention her neck and breasts were being given by Mycroft.

"I- this- we really," she attempted incoherently to complete a sentence.

A long and thin finger was pressed to her lips, Sherlock's finger.

"Shhh, just don't think," whispered Mycroft before biting down rather hard on her neck.

Katherine groaned in a mixture of pleasure and pain. Full and warm lips pressed themselves to hers as a long fingered hand caressed her side and slowly migrated to her thighs where it began to slowly ease them apart. She could feel herself quivering as she grew increasingly aware of the fact that Mycroft's rather large cock was pressed against her back. Her lips broke contact with Sherlock and she leaned her head back to capture Mycroft in a kiss from which he broke away from after a moment.

It was clear he was waiting for something though she wasn't quite sure what that was until she felt something warm probing her folds. Her gaze snapped from the ceiling down to Sherlock whose hands were on the inside of both her thighs holding her still as he explored with his tongue her dripping folds. The sight combined with the feeling sent a sharp wave of pleasure straight to her core and she shivered.

"This is going to hurt," came the soft murmur of Mycroft's voice.

It wasn't a threat, no she knew one of those when she hear one, but more of a warning as his hand grasped her hip and the other began to guide his pulsing cock to her entrance. Sherlock seemed to sense her nervousness because just as Mycroft's tip pressed against her arse hole he flicked his tongue over her clit causing a wave or relaxing pleasure to rush through her. Mycroft pressed into her slowly with the help of Sherlock's constant pleasure filled distractions keeping her relaxed so he didn't hurt her. When he was fully sheathed inside her Mycroft let out a groan and let his forehead fall against her shoulder.

"Fuck, so tight," he muttered his fingers held tightly to her hips as they both adjusted to the new sensation. "Have you ever had anal?"

Katherine shook her head.

"Took it like a champ," he whispered pressing his lips to her neck again.

He seemed to know she needed a minute, but Sherlock didn't because he began to circle her opening with his pointer finger. Katherine shivered and moaned her fingers laced themselves with Mycroft's. Without any warning Sherlock swift thrust three long fingers into Katherine's pussy causing a yelp to spring from her throat, of course she wasn't a virgin but it certainly had been a while. Her thighs shook as Sherlock worked his fingers in and out of her scissoring them apart and stretching her.

"Sherlock," she gasped.

Then the pad of his thumb pressed down on the hood of her clit as he thrust a few more times causing her to whimper.

"Please?" she whimpered.

Mycroft took this as a signal it was okay to move. He pulled out a little bit before sliding back in just as slowly causing Katherine to moan loudly at the combined sensation. Soon their thrusting began to fall in sync and Katherine was sure she wasn't going to last much longer.

"Boys," she whimpered. "I can't-"

"Let. Go." Mycroft hissed flexing his grip on her hips and thrusting inward with extra force punctuating each word.

And she did. Not a minute later did Katherine feel her walls clenching tightly around Sherlock's fingers –causing him to moan- as well as Mycroft's cock as she came. She rode the orgasm out even as Mycroft continued to pump into her; a whimper left her throat a moment later when she felt Sherlock's fingers withdraw from her body.

"Sherlock," she whined as he got to his feet.

He looked down at her a content smile on his lips as he brushed a lock of hair from her face as she gazed as him through heavily lidded eyes. Katherine detangled her fingers from Mycroft's and reached out to cup Sherlock's face and brought his lips to hers in a bruising kiss. There was so much emotional build up from years of pining after his sister in the kiss that is startled Katherine a little bit as Sherlock wrapped his arms around her waist.

Katherine's hand found its way between their bodies and grasped Sherlock's cock tightly in her hand as she began to pump him in time with Mycroft's rough thrusts. She found herself smirking into the kiss as she felt Sherlock's breathing growing more laboured.

"Kat if you- if you keep going I'm going to cum," he gasped into her ear.

Katherine nodded and slowed down as she stared to guide him between her legs. Something stopped them though. Mycroft was pulling Katherine away from Sherlock and toward a couch.

"It'll be easier," he whispered to her breathily leaving a heat lingering on her neck.

Sherlock threw Mycroft a dirty look that said _you did that on purpose_ and followed them to the couch though. Katherine was situated in a position where she was, mostly, supporting herself above Mycroft as he thrust up into her and her legs were spread wide for Sherlock. The warmth of Mycroft's smooth fingers and palm was enveloping her breasts again as Sherlock moved to kiss her and easily peeled away Mycroft's hands –guiding them to her waist- as he started to press into her.

"God you feel so good," he gasped his forehead pressing against hers as he grinned. "Are you ready?"

Katherine nodded, but she hadn't been. The combined sensation of Mycroft's violent rutting into her arse hole like an animal and Sherlock's slow sensual thrusts sent her right over the edge. Her second orgasm came stronger than the first and her body spazumed out of control for a moment during which Mycroft had to force himself to stop so he didn't tear her. A minute or so after she relaxed again into Mycroft's grip and Sherlock's kiss she felt Mycroft tensing under her and his thrusts grew even more erratic, to the point it genuinely hurt her.

"Myk," she whimpered. "It hurts."

Katherine looked up at Sherlock with tears of pain in her eyes and she saw him throw Mycroft a murderous look though it seemed to do nothing to hinder him.

"So. Close," he grunted licking up the side of her neck. "You like the pain don't you Kat?"

Mycroft's nails dug painfully into her hips until he drew blood and Katherine moaned loudly thrusting against Sherlock desperately. The light and soothing sensation of Sherlock's caress turned to the light scrape of his nails down her rib cage as he bit hard into her breast.

"You like being treated like a whore, being fucked in both of your holes. You must be dying. You've already cum twice. Make. It. Three. For. Me," he said in a commanding voice punctuating each sentence with a hard smack to her arse that made a loud cracking sound upon impact.

Sherlock released her breast and ran his nose over the irritated flesh where he'd bitten her as if to apologize for the pain. His eyes flickered to hers as he felt her tightening around him again and he groaned abandoning his slow and sensual attitude and started thrusting harder.

"Next time I'm going to bend you over my desk and make Sherlock watch," Mycroft hissed menacingly in her ear licking the shell of it as he slapped her arse again. "I can play headmaster and you'll be the naughty student."

Katherine huffed in a non-committal fashion. She didn't really hear anything he was saying anymore all that registered was the deep husky tone and the heat of his breath on her neck.

"Sherlock," she yelped grabbing him by the shoulders and pulling him down to kiss her as she came.

There was a fraction of a second between when Katherine came, and when Sherlock followed shortly followed decorating her stomach with his semen, though once his siblings had stilled Mycroft took another minute or so of thrusting before he shot his seed into Katherine's arse.

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><p>After they had all righted themselves and washed up Katherine found herself sitting at her desk staring out the window. She was thinking. All she could do was think. It was puzzling. She couldn't flush the image of Sherlock's angry face when Mycroft was hurting her or the longing there had been in his eyes when he had begged her to stay. She wanted to tell herself it was a dream, but the sting in her arse and the purple bruise on her breast assured her it was not. It was wrong and she knew it, but despite her better judgment she found herself developing an unnatural soft spot for those blue eyes that she had never really taken any notice of before.<p>

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><p><strong>AN: SO, Reveiw and let me know what you think? This _could_ become a story, but I don't know xD **


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